The invention relates to urological endoscopes, particularly resectoscopes, of the type comprised of a hollow cylindrical sheath through which passes, besides an endoscopic optical viewing arrangement, and possibly also an operating instrument (such as a loop-shaped resecting electrode), clear rinsing water, and provided with means for effecting the return flow of the rinsing water discharged from the distal end of the endoscope.
Resectoscopes are most often used to remove pathological tissue from the prostate gland. For this purpose, the sheath of the resectoscope must be inserted into the urethra to such an extent that the distal end of the sheath, and the reciprocating resecting electrode loop therein, are located in the operating zone. To make the field of view clear during the resecting operation in the case of electroresection, clear rinsing water is fed into the operating zone through the resectoscope sheath. The clear rinsing water, made turbid as a result of becoming mixed with blood at the operating zone, is removed from the operating zone by suitable means. With known constructions, there is provided, for the purpose of effecting the removal of the turbid rinsing water, a return-flow conduit disposed inside the resectoscope sheath extending all the way to the distal end of the resectoscope sheath and of course having a diameter considerably smaller than that of the resectocope sheath. Such an arrangement of the return-flow conduit for the rinsing water complicates to a considerable degree the cleaning of the resectoscope. Additionally, the rinsing effect, provided for the purpose of making clear the field of view, is less than satisfactory, because the clear rinsing fluid discharged from the distal end of the resectoscope sheath for the most part is directly diverted into the inflow port of the return-flow conduit, so that sizable amounts of the rinsing fluid in the bladder, made turbid by mixture with blood, do not actually enter the return-flow conduit.